Described is an ultrasound diagnostic imaging apparatus which includes an ultrasound probe and which generates ultrasound image data sets for displaying an ultrasound image. The ultrasound diagnostic imaging apparatus includes a transmitting unit which performs ultrasound scanning for a plurality of times so that a part of or all of scan regions overlap in a plurality of different directions, an image processing unit which generates a plurality of ultrasound image data sets according to the receive signals and an anisotropic aspect evaluation unit which evaluates an anisotropic aspect of ultrasound wave reflection in the subject according to at least either of the ultrasound image data sets and the receive signals. In the ultrasound diagnostic imaging apparatus, the image processing unit generates synthetic image data in which the plurality of ultrasound image data sets are synthesized according to an evaluation result of the anisotropic aspect evaluation unit.